Expansion member for electric heating devices.



H. P. BALL.

EXPANSION MEMBER FOR ELEGTRIG HEATING DEVICES.

APPLICATION FILED DBO.14, 1912,

1,093,754. Patented Apr. 21, 19m

Witnesses Im/enbor Henry Price Ball Hi5 dTt/oorneg UNITED STATES PATENT OFFICE.

HENRY PRICE BALL, OF PITTSFIELD, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

EXIPANSTON MEMBER FOR ELECTRIC HEATING DEVICES.

Specification of Letters Patent.

Patented Apr. 21, 1914.

Application filed December 14, 1912. Serial No. 736,707.

To all 11']: out it 777 (13 concern Be it known that I, Ilnnnr PRICE Bun, a citizen of the United States, residing at Pittsfield, county of Berkshire, State of Massachusetts, have invented certain new and useful Improvements in Expansion Members for Electric Heating Devices, of which the following is a specification.

My invention relates to electric heating devices comprising sheet metal portions in which heating units are mounted.

One application of myinvention is to sheet metal incased electrically heated cooking ranges having mounted in the top or other surface thereof a flat metal incascd stove or a plurality of the same. In such a structure, the heating unit is necessarily raised to a much higher temperature than the surrounding casing and the expansion due to such heating will cause the surrounding sheet metal to warp unless provision is made for otherwise allowing for said expansion. It is desirable that this be accomplishcd without disturbing the continuity of the sheet metal casing for the reason that any spaces therein will increase the accumulation of grease and dirt.

The object of my invention is to provide means for compensating for the expansion of the heating unit without warping the surrounding casing of the range and which will still preserve the continuity of the said casing.

In carrying out my invention I provide an expansion member which surrounds the heating unit and is of such shape. that it will be flexed by the expansion of the heating unit a suflicient amount to compensate for said expansion without disturbing the rest of the sheet metal casing. This expansion member, which is in fact a part of the sheet metal casing, I prefer to make separable from the main portion of the latter for the reason that it is more easily constructed than if it is made integral with said portion. The greater flexibility of the expansion member compared to the rest of the casing is secured by making it sinuous in cross-section, or at least so that a portion thereof is located outside the plane of the rest of the casing.

This allows the bending of the expansion ing is much greater than if the expansion member were not interposed and this allows for sufficient drop in. temperature between the heating unit and the said casing so that there will be no warping of the latter due to difference in the temperature of its parts.

My invention will be more clearly understood by referring to the accompanying drawing in which Figure 1 is a partial vertical section of a range top equipped with my invention. Fig. 2 is a plan view of the same.

In the drawing, 10 is a portion of a sheetmetal top of a range having an aperture formed therein for the reception of the metal incased electric resistance heating unit or stove 12 which is provided with suitable terminal connections 13 and leads 14:. The stove 12 is mounted preferably by means of a bolt and nut connection 15 on the inner annular flange 16 of the expansion member 17. The said. expansion member is sinuous in section comprisim in addition to the inner flange 16 the angul arly disposed outer flange 18 and the web portion 19 connecting the said flanges. The expansion member is preferably made in the form of a continuous, annular, unbroken piece. Pins 20 attached to the flange 18 fit loosely in perforation 21 in the countersunk rim 22 forming partof the sheet metal casing 10.

When the metal incasedunit 12 is heated it will enlarge in circumference. This expansion of the unit causes a flcxure of the expansion member 17 due to the pressure from the unit. Moreover-the difference in temperature between the inner and outer portions of the expansion member will cause the warping of the same so as to increase the inner circumference thereof. In the case of the specific structure shown this will cause the unit 12 to be raised slightly. However, this is not material, the important point being that the change in shape of the expansion member serves to accommodate for the increased size of the heating unit. The drop in temperature across the expansion memher will serve to prevent the inner portion of the sheet metal casing from being raised materially above the temperatureof the sidered as coming within the scope of my invention which is set forth in the following claims.

That I claim as new and desire to secure by Letters Patent of the United States, is

1. The combination in an electrically heated device, of a sheet metal casing a metal incased electric resistanceunit mounted in an aperture therein and an expansion member located between the said heating unit and said casing of greater flexibility than the latter.

2. 'lhe combination in an electrically heated device, of a sheet metal casing, a metal incased heating unit mounted in an aperture therein and an expansion member located between said heat unit and said casing having a portion thereof extending outside of the plane of said casing.

3. The combination in an electrically heated device, of a sheet metal casing, an expansion member mounted in an. aperture therein and an electric resistance heating unit substantially flush with said casing and mounted upon the said expansion member, said expansion member being sinuous in section.

4. The combination in an electricallyheated device with a sheet metal casing having an aperture therein, a metal incased electric resistance heating unit substantially flush with said casing located in said aperture and a continuous expansion member extending between the said heating unit and said casing and having a portion thereof extending outside of the plane of said casing.

In witness whereof, I have hereunto set my hand this 10th day of December, 1912.

HENRY PRICE BALL.

Witnesses:

H. 1B. DAVERIN, M. J. REYNOLDS. 

